ERP5TypeFunctionalTestCase: take screenshot and dump the page on error

This is not really for errors during the test itself, but for errors when
ERP5TypeFunctionalTestCase manipulates browser to execute selenium test.

product/ERP5Type/tests/ERP5TypeFunctionalTestCase.py

@@ -49,7 +49,7 @@ import certifi
 import urllib3
 from selenium import webdriver
 from selenium.webdriver.common.by import By
-from selenium.webdriver.support.ui import WebDriverWait
+from selenium.webdriver.support.ui import WebDriverWait as _WebDriverWait
 from selenium.webdriver.support import expected_conditions as EC
 from selenium.webdriver.remote.remote_connection import RemoteConnection
 
@@ -167,6 +167,31 @@ class Xvfb(Process):
     logger.debug('Xvfb : %d', self.process.pid)
     logger.debug('Take screenshots using xwud -in %s/Xvfb_screen0', self.fbdir)
 
+
+class WebDriverWait(_WebDriverWait):
+  """Wrapper for WebDriverWait which dumps the test page and take a
+  screenshot in case of error.
+  """
+  def until(self, *args):
+    try:
+      return super(WebDriverWait, self).until(*args)
+    except:
+      logger.exception("unable to find login field, dumping the page")
+      try:
+        with open(os.path.join(log_directory, 'page.html'), 'w') as f:
+          f.write(
+            self._driver.execute_script(
+                  "return document.getElementById('testSuiteFrame').contentDocument.querySelector('html').innerHTML"))
+      except:
+        logger.exception("error when dumping page")
+      try:
+        with open(os.path.join(log_directory, 'page-screenshot.png'), 'wb') as f:
+          f.write(self._driver.get_screenshot_as_png())
+      except:
+        logger.exception("error when taking screenshot")
+      raise
+
+
 class FunctionalTestRunner:
 
   # There is no test that can take more than 6 hours